Wheel driven articulated bulldozer

ABSTRACT

This invention relates to a remotely controlled toy in the form of a wheel driven, articulated bulldozer. The bulldozer consists of front and rear body sections, each equipped with a pair of supporting wheels, with all the wheels arranged to be driven through remote control, forward or backward, always in unison with one another. The front and rear sections of the bulldozer are connected for relative movement about a vertical axis for steering purposes, and remotely controlled means is provided for relatively adjusting the sections toward the right or toward the left, about such axis. The front and rear sections are connected with freedom for tilting relative to one another. The front section includes a bulldozer blade which may be raised and lowered by remote control.

United States Patent 1 Gagnon l l WHEEL DRIVEN ARTICULATED BULLDOZER [76] Inventor: Robert A. Gagnon, Star Rt. 2, Box

944, Trail, Oreg. 97543 22 Filed: Oct. 18, 1972 211 Appl. No.: 298,560

[ July 24, 1973 Primary Examiner-Louis G. Mancene Assistant Examiner-Jack Q. Lever, Jr. Attorney-Clarence M. Crews [57] ABSTRACT This invention relates to a remotely controlled toy in the form of a wheel driven, articulated bulldozer. The bulldozer consists of front and rear body sections, each equipped with a pair of supporting wheels, with all the wheels arranged to be driven through remote control, forward or backward, always in unison with one another. The front and rear sections of the bulldozer are connected for relative movement about a vertical axis for steering purposes, and remotely controlled means is provided for relatively adjusting the sections toward the right or toward the left, about such axis. Thefront and rear sections are connected with freedom for tilting relative to one another. The front section includes a bulldozer blade which may be raised and lowered by remote control.

9 Claims, 8 Drawing Figures WHEEL DRIVEN ARTICULATED BULLDOZER This invention relates to a toy machine in the form of a wheel driven bulldozer which is of simple and inexpensive, but of sturdy, construction.

There are four essential operations, allsubject to remote control, to-wit: (l) the raising and lowering of a bulldozer blade at the front of the machine; (2) the relative turning about a vertical axis, for steering purposes, of wheel supportedfrontand rear sections of the machine; (3) the driving of the machine either forward or backward at the will of the operator; and 4) the provision for relative lateral tilting of the frontand rear sections.

Other objects andadvantages will hereinafter appear.

In the drawing forming part of this specification,.

FIG. 1 is a view in side elevation of a toy machine which constitutes a practical and advantageous embodiment of the invention, with portions broken away for revealing normally concealed structure;

FIG. 2 is a fragmentary view in side elevation showing only the forward end of the machine with the bulldozer blade raisedto ahigher level than in FIG. 1;

FIG. 3 is a fragmentary plan view showing the front and rear sections turned out of. alignment for causing the machine to change direction, there being portions broken away in this figure for revealing underlying structure;

FIG. 4 is a plan view of the complete machine with the front and rear sectionsin alignment, and with the rear frame member shown in horizontal section on the line 4--4 of FIG. 1;

FIG. 5 is a diagrammatic view of the complete machine togetherwith the remote control unit;

FIG. 6 is an electrical diagramshowing how the machine is operated'from a power and switchunit by remote control;

FIG.'7 is a fragmentary plan view of the frontend of the machine, partly broken away, showing an alternative form of drive train for raising and lowering the blade; and

FIG. 8 is a fragmentary view in side elevation, partly broken away, showing in a somewhat diagrammatic manner the alternative drive train ofFIG. 7 for raising and loweringithe blade.

The illustrative toy 10 comprises a front body section 12' which is supported by wheels 14, 14 fast on a common motor driven axle 16', and a rear. body section 18 which is supported by wheels 20, 20 which are fast on a common motor driven axle 22.

The sections 12 and I8-are connected to one another with freedom for lateral tilting about a longitudinally extending horizontal axis in response to unevenness of the terrain over which the vehicle is driven and for relative turning about a vertical axis for the purposeof steering adjustment.

The rear section 18 provides a fore-and-afthorizontal stationary shaft 24upon which a forwardly reaching yoke 26 is rotatively mounted. Upperand lowerarms 28 of the yoke 26 are mounted with freedom for angular movement about the vertical axis of upper and lower trunnions 30 of the front section 12. The trunnions 30 may take the form of headedbolts threaded into the frame of front body section 12 and fixed against backing out. It is an important point that the trunnion axis is located substantially midway between the front and rear axles l6 and 22. This promotes tracking. of the wheels on curves, tends to cause the front and rear vehicle sections to shift equally during adjustment where there is no obstruction, and permits eitherend of the vehicle to be readjusted readily when adjustment of the other end is obstructed.

Steering adjustment is effected through operation of a reversible electric motor 32 which is mounted within the body of the rear end 18 of the vehicle. Drive may be effected through any suitable speed reducing gearing. As shown the motor shaft 34 has fast upon it a worm 3,6 which drives a worm gear 38 that is freely rotatable in a shaft 40. A comparatively small gear 42 fast with gear- 38 drives a larger gear 44 which is free to turn on, and relative to, output shaft 46. A comparatively small gear 48 fast with gear 44 drives a larger gear 50 fast on shaft 40. A broad gear 52 of small diameter, also fast on shaft 40, drives a comparatively large gear 54 which is rotatively mounted on output shaft 46. The gear 54'is notonly free to turn relative to shaft 46 but it is also free to slide along the shaft. A compression coil spring 56 surrounds the shaft 46, bearing at one end against a fixed abutment 58 and at the other against a face of the gear 54. The spring 56 urges the gear 54' into frictional driving engagement with a rubber-faced disc 60. The disc 60 is fast on the output shaft 46. The gear 54 and the rubber-faced disc 60 form a slip clutch that permits the gear 54 to turn even after the shaft 46has reached a limit of movement, for as long: as the motor continues to be driven.

The shaft 46 has fast upon it a crank 62 whose outer end is connected through a link 64 to a short fixed arm of the front body member 12. The link 64 and the arm 66 are interlooped at their adjacent ends to provide a universal connection.

Asseen in FIGS. 1 and 4 the wheels 14 and 20 at each side of the vehicle are disposed in coplanar relation, the crank at this phase extending straight down, as shown'in FIG. 1. In FIG. 3 the link has been thrust forward and in consequence the wheels are set to turn left. I-Iad the link instead been shifted rearward, the wheels would have been set to turn right.

Since the toy is intended to simulate a bulldozer and to perform the work of a bulldozer on a miniature scale, it is provided that a working blade 68 at its forward end which can be raised or lowered through remote control at the will of the operator. The blade 68 has rigid arms 70 through which it is rockably supported from the opposite ends of a stationary transverse shaft 72. The blade 68 also includes ears 74 through which it is connected to motor operated means for lifting and lowering it.

The blade is raised and lowered through operation of an electric motor 76 which is mounted in the front end of the vehicle. The motor shaft 78'has fast upon it a small gear'80 which, through a large gear 82, small gear 84,1argegear 86, and small gear 88, drives a large gear which is fast on a sloping shaft 92. The shaft 92 is connected through a universal joint 94 to drive a forwardly sloping threaded shaft 96, the latter shaft being threaded through a nut 98. As best seen in FIG. 5, the nut 98 is mounted upon and between the cars 74 with freedom for rocking motion, to accommodate tilting of the threaded shaft 96 as the nut is raised and lowered along the shaft by rotation of the shaft.

The rear wheel drive is shown in detail in FIG. 4.

It is a duplicate of the front wheel drive, so that a showing and description of one will suffice for both.

A motor 100r through a pinion 102 drives a crown gear 104 which is revolubly mounted on a fixed shaft 106, but is restrained against movement longitudinally of the shaft. A small gear 108, fast with the crown gear 104, drives a large gear 110 which is revolubly mounted on the axle 22. A small gear 112, fast with the gear 110, drives a large gear 114 which is revolubly mounted on the shaft 106, and finally a small gear 116, fast with the gear 114, drives a large gear 118 fast on the axle 22. Suitable collars are provided for restricting gears against endwise movement relative to shafts on which the gears are revolubly mounted. The gear trains described have the merit that they are very compact and may therefore be enclosed in a space of small compass. Any suitable reduction gearing having like capability and like characteristics would serve acceptably, however.

As previously noted, the front wheel drive may advantageously duplicate the rear wheel drive.

In FIG. 5 the bulldozer is shown together with a switch and power unit 128 through which the bulldozer is remotely controlled. All the wires that run from the unit 128 to the motors on the bulldozer 10 are combined, in insulated relation to one another, into a single flat cable 130.

The motors 32, 76, l00f and 100r are reversible direct current motors whose fields are energized by permanent magnets. Each of them can be reversed by reversing the direction of current flow through its armature. The electrical diagram of FIG. 6 shows the circuitry of the motors and of the control unit.

The unit 128 includes a battery 132 (or a rechargeable energizer) and a series of switch operating buttons. The opposite poles of the battery 132 are connected to conductors 134 and 136. Branch conductors 32a and 32e of conductor 134 are associated with branch conductors 32d and 32fof conductor 136, and all four conductors are associated with a switch 32s whose ends are conductive but are insulated from one another. Opposite ends of the switch are constantly connected through conductors 32b and 32c with the opposite terminals of motor 32. The switch 32s is rocked clockwise by a button 32g to complete a circuit from battery 132 through conductors 134 and 32a, a first conductive segment of switch 32s, conductor 32b, the armature of motor 32, conductor 32, a second conductive segment of switch 32s, and conductors 32d and 136. The switch is self-neutralizing when the button 32g is released.

The switch 32.: is rocked counter-clockwise by a button 32h to complete a circuit from battery 132 through conductors 134 and 32e, the second conductive segment of switch 32s, conductor 320, the armature of motor 32, conductor 32b, the first conductive segment of switch 32s and conductors 32f and 136.

Button 76g is depressed to rock switch 76s clockwise for energizing motor 76 to lower the blade 68, and button 76h-is depressed for energizing motor 76 to raise the blade. The circuitry is essentially the same as that already described for the motor 32. Corresponding parts have been similarly lettered and no further detailed description is necessary.

Button 1003 is depressed for driving the bulldozer forward and button 100k is depressed for driving the motors F and 100R are connected in parallel for operation in unison, the branch conductors to motor 100R being designated 100Ra and 100Rb. The concurrent and harmonious operations of the motors 100R and 100F from a common control is advantageous. The greatest utilization of power is required for driving the vehicle forward and backward and two motors are devoted to this service. The advantages of four wheel drive are also realized.

An alternate system for controlling the raising and lowering of the blade 68 is disclosed in FIGS. 7 and 8. A motor 200 is provided for this purpose as a substitute for motor 76 in the front end 12 of the vehicle. As shown in FIG. 7 and indicated diagrammatically in FIG. 8, a small gear 202 on the output shaft 204 of motor 200 drives a large gear 206 which is mounted on a shaft 208. A small gear 210 fast with gear 206 drives a large gear 212 which is fast on a shaft 214. A broad gear 216 of small diameter also fast on shaft 214, drives a large gear 218 which is revolubly and slidably mounted on the shaft or axle 219. A collar 220, fast on shaft 219, acts through a compression coil spring 222 to press the gear 218 yieldingly against a rubber-faced disc 224. The disc 224 is fast on the shaft 219 so that the gear 218 and the disc 224 form a slip clutch through which a crank 228, integral with the disc, is driven. The crank 226 is connected through a link 228 with the blade ear 74.

When alternative blade drive of FIGS. 7 and 8 is used, the electrical diagram of FIG. 6 would still apply, but with the motor 200 substituted for the motor 76.

I have described what I believe to be the best embodiments of my invention. What I desire to cover by letters patent is set forth in the appended claims.

I claim:

1. A toy comprising, in combination, a wheel driven bulldozer and a portable remote power and control unit therefor, said bulldozer including a. front and rear body sections, each of which includes a pair of supporting wheels,

b. means connecting the body sections with freedom for relative rocking movement about a longitudinally extending horizontal axis; and, for steering purposes, with freedom for controlled relative movement about a vertical axis;

c. a bulldozer blade together with a blade carrier mounted at the front of the front body section and a reversible carrier operating motor operable to raise and lower the blade,

(I. reversible motor operated means constructed and arranged to drive the front wheels and the rear wheels forward or backward in unison;

e. reversible motor operated means constructed and arranged relatively to turn the front and rear body sections, and

f. switch means included in the remote power and control unit for selectively driving f1. the wheel operating motor means forward or backward, f2. the blade raising and lowering motor in raising or lowering direction, and f3. the body turning motor in either of two opposite directions.

2. A toy as set forth in claim 1 in which separate motors are provided on the front body section and on the rear body section, respectively, for the front wheels and for the rear wheels, which motors are of like construction and are coordinately connected to the wheels which they drive, and in which the switch means controlling said motors cause the motors invariably to be driven in harmony with one another.

3. A toy as set forth in claim 1 in which the reversible body turning motor, mounted on one of the body sections, is connected to the other body section through a motor driven shaft, a crank fast on the shaft, and a link.

4. A toy as set forth in claim 1 in which the vertical axis about which the front and rear body sections turn relative to one another is located substantially equidistant from the axes about which the front and rear wheels turn.

5. A toy as set forth in claim 1 in which all electrical conductors which run from the power and control unit to the motors on the vehicle sections are combined into a single flat cable in which they are insulated from one another.

6. A toy as set forth in claim 1 in which the blade raising and lowering means comprises an internally threaded member mounted on the blade and a rotary motor driven, threaded shaft screwed through said threaded member.

7. A toy as set forth in claim 1 in which limits of movement are imposed on motor operated parts and slip clutches are included between such parts and their operating motors so that an involved motor may continue to operate without strain after the involved part has been arrested at its limit of movement.

8. A toy as set forth in claim 1 in which the blade raising and lowering means comprises an output shaft, a motor driven gear revolubly mounted on the shaft, a slip clutch connecting the gear to drive the shaft and blade raising and lowering means responsive to rotation of the shaft.

9. A toy as set forth in claim 1 in which the blade raising and lowering means responsive to rotation of the shaft comprises a crank fast on the shaft and a link which connects the crank to the blade. 

1. A toy comprising, in combination, a wheel driven bulldozer and a portable remote power and control unit therefor, said bulldozer including a. front and rear body sections, each of which includes a pair of supporting wheels, b. means connecting the body sections with freedom for relative rocking movement about a longitudinally extending horizontal axis; and, for steering purposes, with freedom for controlled relative movement about a vertical axis; c. a bulldozer blade together with a blade carrier mounted at the front of the front body section and a reversible carrier operating motor operable to raise and lower the blade, d. reversible motor operated means constructed and arranged to drive the front wheels and the rear wheels forward or backward in unison; e. reversible motor operated means constructed and arranged relatively to turn the front and rear body sections, and f. switch means included in the remote power and control unit for selectively driving f1. the wheel operating motor means forward or backward, f2. the blade raising and lowering motor in raising or lowering direction, and f3. the body turning motor in either of two opposite directions.
 2. A toy as set forth in claim 1 in which separate motors are provided on the front body section and on the rear body section, respectively, for the front wheels and for the rear wheels, which motors are of like construction and are coordinately connected to the wheels which they drive, and in which the switch means controlling said motors cause the motors invariably to be driven in harmony with one another.
 3. A toy as set forth in claim 1 in which the reversible body turning motor, mounted on one of the body sections, is connected to the other body section through a motor driven shaft, a crank fast on the shaft, and a link.
 4. A toy as set forth in claim 1 in which the vertical axis about which the front and rear body sections turn relative to one another is located substantially equidistant from the axes about which the front and rear wheels turn.
 5. A toy as set forth in claim 1 in which all electrical conductors which run from the power and control unit to the motors on the vehicle sections are combined into a single flat cable in which they are insulated from one another.
 6. A toy as set forth in claim 1 in which the blade raising and lowering means comprises an internally threaded member mounted on the bLade and a rotary motor driven, threaded shaft screwed through said threaded member.
 7. A toy as set forth in claim 1 in which limits of movement are imposed on motor operated parts and slip clutches are included between such parts and their operating motors so that an involved motor may continue to operate without strain after the involved part has been arrested at its limit of movement.
 8. A toy as set forth in claim 1 in which the blade raising and lowering means comprises an output shaft, a motor driven gear revolubly mounted on the shaft, a slip clutch connecting the gear to drive the shaft and blade raising and lowering means responsive to rotation of the shaft.
 9. A toy as set forth in claim 1 in which the blade raising and lowering means responsive to rotation of the shaft comprises a crank fast on the shaft and a link which connects the crank to the blade. 